Download Atomic Theory Notes

Chemistry
Atomic Theory
Ms. Mavi/ Ms. Gogolin
Atomic Theory Notes
Atoms
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Matter is anything that takes up space and has mass. All matter is made of atoms.
Atoms are the basic building blocks of matter. They make up everything around us; Your
desk, the board, your body, everything is made of atoms!
Atoms are too small to see without powerful microscopes.
Subatomic Particles
Subatomic Particle
Charge
Location
Proton
Positive (+)
Nucleus or “Core”
Neutron
No Charge (0)
Nucleus or “Core”
Electron
Negative (-)
Electron Cloud
Atomic Structure
Electron Cloud:
• Electrons orbit the
nucleus.
Nucleus or “Core”:
• Protons and Neutrons are found in the
nucleus.
Chemistry
Atomic Theory
Ms. Mavi/ Ms. Gogolin
Atomic Theory Over Time
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Because we cannot see atoms, we use models to teach and learn about atoms.
The atomic theory has changed over time as new technologies have become available.
o Remember: Scientific knowledge builds on past research and experimentation.
Scientist
Discovery/ Theory
John Dalton
All matter is made of atoms. Atoms are too small to
see, indivisible and indestructible. All atoms of a given
element are identical.
J.J. Thompson
Discovered the negative electron, and predicted that
there also must be a positive particle to hold the
electrons in place.
Ernest Rutherford
Discovered the nucleus of an atom and named the
positive particles in the nucleus “protons”. Concluded
that electrons are scattered in empty space around
the nucleus.
Model